High-resolution spectroscopic of red giants stars in NGC 2360

Open clusters are excellent laboratories to test our knowledge of the formation and evolution of the two components of the disk (thick and thin disk), and stellar structure and evolution, since the stars present the same age and distance reducing the uncertainties associated with field stars of the Galaxy. NGC 2360 is an open cluster with 0.85 Gyr, with galactocentric distance equal to 9.28 Kpc and height equal to -30 pc. We determine to 15 stars in the NGC 2360 using high resolution spectroscopy the atmospheric parameters and the chemical composition for Fe, Ni, Cr, Ca, Mg, Si, Ti, Na, Al, Ba, Y, Zr, La, Ce and Nd with measures of equivalent widths of absorption lines, and spectral synthesis for C, O and N. The spectra of 14 stars were obtained with FEROS at the 2.2m ESO telescopes at La Silla (Chile). Only one star was observed with UVES/VLT at Paranal Observatory. Atmospheric parameters and abundances were determined using the LTE atmosphere models of Kurucz and the spectral analysis code MOOG. The abundance of alpha and iron-peak elements of NGC 2360 are typical disk abundances. We also observed a slight overabundance of the elements generated by the s-process in NGC 2360 with respect to field stars of the disk. The overabundance of the elements generated by the s-process occurs in young open clusters and may be linked to high-efficiency of these nucleosynthesis in low-mass stars (<1.5M_{odot}). However, this high-efficiency has not been explained by the stellar evolutionary models. Additional observations and high resolution spectroscopic analysis of intermediate-age open clusters (like NGC 2360) are necessary to confirm the slight overabundances of s-process elements with relation to field stars of the disk and old open clusters.